Speech enhancement in a vehicle is a challenge. Some systems are susceptible to interference. Interference may come from many sources including engines, fans, road noise, and rain. Reverberation and echo may further interfere, especially in hands-free systems.
When used in a vehicle, a microphone may be positioned within an interior to receive sound from a driver or a passenger. When positioned away from a speaker, the desired signal strength received by the microphone decreases. As the distance increases the signal becomes more susceptible to noise and distortion.
When focusing on cost, a vehicle manufacturer may limit the number of microphones used in cars and limit the processing power of the devices that process their output. A manufacturer's desire to keep costs down may reduce the quality and intelligibility to a point that is much lower than their customers' expectations. There is room for improvement for a speech enhancement system, especially in vehicle interiors. There is a need for a system that is sensitive, accurate, has minimal latency, and enhances speech at a low computational cost.